1. Field of the Invention
The present invention relates to a silver alloy used in an organic electroluminescent panel and, more particularly, to a silver alloy suitably serving as an auxiliary electrode or a conducting line in an organic electroluminescent panel.
2. Description of Related Art
The organic electroluminescent panel is a device that utilizes the organic functional materials, which radiate spontaneously to achieve image display. According to the molecular weight of the organic functional materials, the organic electroluminescent panel is classified as two types, i.e. the small molecule OLED (SM-OLED) and the polymer light-emitting device (PLED). On the other hand, the organic electroluminescent panel is also classified as two types, i.e. the active matrix OLED (AM-OLED) and the passive matrix OLED (PM-OLED) according to the driving method.
Currently, most of the semiconductor and the flat panel displays use chromium (Cr) to form the conducting lines or the auxiliary electrodes. However, chromium has a high resistance and high power consumption. Therefore, researchers continue to look for a metal that has low resistance to form the conducting lines or the auxiliary electrodes. In the past, it had been suggested to form the conducting lines using silver. As there were no suitable and stable etchants for the silver, it was not used widely.
In particular, when the silver is exposed to the atmosphere containing sulfur, it reacts with the sulfur and becomes black on its surface. In another aspect, when the silver is exposed to ammonia, it produces a silver-ammonia complex compound, which blurs the originally shiny surface of the silver. Moreover, such kinds of reactions will keep growing and dispersing whereby the surface quality of the silver is seriously damaged so it is not suitable to use pure silver to form the conducting lines or the auxiliary electrodes.
It was also suggested to use aluminum or copper that were commonly used in semiconductor manufacturing to form the conducting lines or the auxiliary electrodes. However, aluminum or copper often cause problems of electron migration, hillock, and corrosion in forming the conducting lines or the auxiliary electrodes, so they are not suitable materials for the conducting lines and the auxiliary electrodes, either. IZO alloy was also suggested to cooperate with molybdenum (Mo) for forming the conducting lines or the auxiliary electrodes. Nevertheless, that alloy has not been widely used in the flat panel display devices so far due to the relatively high cost and complex processing.
Therefore, it is desirable to provide a material with low resistance, high thermal conductivity, and good adhesion for forming the conducting lines or the auxiliary electrodes of the flat panel display device or the semiconductors to mitigate and/or obviate the aforementioned problems.